In recent literature there is unanimous agreement about children's pragmatic competence in drawing scalar implicatures about some , if the task is made easy enough. However, children accept infelicitous some sentences more often than adults do. In general their acceptance is assumed to be synonymous with a logical interpretation of some as a quantifier. But in our view an overlap with some as a determiner in under-informative sentences cannot be ruled out, given the ambiguity of the experimental instructions and the attitude of trust by children in adults. Our study investigated this hypothesis with different experimental manipulations. We found that when the experimenter's intentions are clear (Experiment 1, all / some order effect; Experiments 2 and 4, conditions 2 and 3), under-informative sentences are usually rejected; otherwise (Experiment 1, some / all order effect; Experiments 3 and 4, control condition) they are accepted. However, analysis of verbal protocols indicated that pragmatically infelicitous sentences are accepted, with some interpreted mostly as a determiner, irrespective of the function of some as a quantifier. Acceptance is not in itself synonymous with a logical interpretation of some as a quantifier